1. Field of the Invention
This invention relates to removable carriers which interconnect memory storage devices with computers. More particularly, this invention relates to folding handle carrier assemblies.
2. Previous Art
Computer memory storage devices have changed since the inception of the floppy disk drive in the early 1970's. Optical disk drives, hard disk drives and digital tape drives are examples of currently used memory storage devices. The development of such memory storage devices and related systems has been instrumental in increasing data storage capacity as well as data storage and recall speed.
Floppy disk drives are especially useful for transferring computer work product from one personal computer (PC) to another. Unlike work product transferred via hard copy, the work product transferred via floppy disk does not have to be re-created by a keyboard operator for example. Multiple users, each at a different PC, may modify the computer work product until the work product is complete. This increases computer user efficiency.
Floppy disk drives have limited capacities. Early floppy disk drives had a storage capacity of 360 kilobytes. Subsequent versions had capacities of 720 kilobytes and 1.2 megabytes. There are now floppy disk drives having storage capacities of 2.88 megabytes. These greater capacity floppy disk drives are smaller and faster than the early floppy disk drives. It is expected that even greater capacity memory storage devices will be available in the near future.
Hard disk drives have greater storage capacities than floppy disk drives. Hard disk drives typically recall and store data more rapidly than a floppy disk drive. This is typically why hard drives are preferred. Most PC's, for example, include a hard disk drive which provides considerable storage capacity. Because hard disk drives generally are not easily removable, PC's typically include at least one floppy disk drive. This facilitates the transfer of data from one PC to another. Unfortunately, increased demand for data transfer capabilities has outpaced floppy disk drive capabilities. For example, floppy disk drives having a 2.88 megabyte storage capacity can not rapidly transfer large amounts of data (e.g. 1 gygabyte) between PC's as is often desired.
The problem of increasing data transfer capabilities is not limited to PC's. The same difficulty is faced with work stations and main frame computers. Accordingly, systems having removable hard disk drives have evolved to enable the transfer of large amounts of data. Workstations such as the Sun.RTM., and others, use removable hard disk drives to transfer data. Such systems also have improved computing power and speed over PC based computers with far less cost than main frame computers. Such workstations are becoming increasingly more cost effective and therefore more popular.
Work stations often rely upon multiple memory storage devices. One way of housing these multiple memory storage devices and connecting these devices to a work station computer is with a "shoe box". A shoe box is an enclosure which houses many memory storage devices. These devices are stacked in close proximity and electrically connected within the shoe box.
One of the remarkable capabilities that can be gained from using a shoe box is the ability to remove a memory storage device while the computer system continues operation. This capability is known as "hot swapping". Hot swapping enables computer systems to continue operation while memory storage devices are removed, replaced or exchanged.
Removal, replacement or exchange of memory storage devices must be done with great care. The installation and exchange of such electrical devices can cause the electrical connections to become damaged, sometimes beyond minor repair. Replacement of an entire mother board or a controller may be required in cases of severe damage. To avoid damage to the electrical connectors, alignment of the connectors of different electrical devices with the host computer or the shoe box must be precise.
Typically, a shoe box includes an equipment slide which receives the carrier during hot swapping. The equipment slide guides the carrier into the shoe box so that electrical connectors on the memory storage device and in the shoe box align. Still, electrical connectors sometimes misalign and become damaged. What is needed is a carrier which provides improved alignment between a carrier and an equipment slide.
After the carrier mates with the equipment slide, and the respective electrical connectors align, relative movement between the carrier and the equipment slide is still possible. Such movement is the result, in part, of high frequency vibrations generated from the memory storage device attached to the carrier. Over time, relative movement may misalign and damage the electrical connectors. What is needed is a carrier which securely locks with the equipment slide to prevent relative movement between the equipment slide and the carrier.
A variety of locking mechanisms have been developed for various carrier configurations. A carrier developed by Sun Microsystems Inc., for example, has a base, a folding handle with a handle grip and a plastic hook-shaped lock attached at the handle grip. The carrier supports a memory storage device with an electrical connector. The base has an extended end which opposes the electrical connector. The lock snaps with the extended end of the base when the handle folds against the base. The lock and the extended end of the base consumes valuable space. What is needed is a carrier which conserves space.
Various memory storage devices have varying heights (e.g. standard capacity hard disks, low profile hard disks, etc.). To accommodate the various memory storage device configurations, the handle length must be long enough to enable the handle to fold over the memory storage device. In the past, a folding handle carrier having a handle configured for attachment to a low profile disk drive would not be compatible with a larger standard profile disk drive. (The term "profile" describes the height of the disk drive.) Accordingly, folding handle carriers which rely on a handle lock at one end of the base of carrier are not adapted for use with both low profile disk drives and disk drives with the standard configuration. In each application, a separately configured carrier must be used. What is needed is a folding carrier which does not rely on a lock at one end of the base and which can accommodate various memory storage device configurations.